| Residency | Year | |||||||||
| 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | |
| Total | 132 | 164 | 182 | 201 | 221 | 272 | 248 | 315 | 387 | 408 |
| U.S. Resident | 128 | 160 | 178 | 196 | 215 | 266 | 243 | 311 | 385 | 406 |
| Nonresident Alien | 2 | 1 | - | 1 | - | - | - | 2 | 1 | 1 |
| Unknown | 2 | 3 | 4 | 4 | 6 | 6 | 5 | 2 | 1 | 1 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| U.S. Resident | 97.0% | 97.6% | 97.8% | 97.5% | 97.3% | 97.8% | 98.0% | 98.7% | 99.5% | 99.5% |
| Nonresident Alien | 1.5% | 0.6% | - | 0.5% | - | - | - | 0.6% | 0.3% | 0.2% |
| Unknown | 1.5% | 1.8% | 2.2% | 2.0% | 2.7% | 2.2% | 2.0% | 0.6% | 0.3% | 0.2% |